docs: def tag_add(package, tag, pkghash):
      """
      Add a new tag for a given package hash.
  
      Unlike versions, tags can have an arbitrary format, and can be modified
      and deleted.
  
      When a package is pushed, it gets the "latest" tag.
      """
      team, owner, pkg = parse_package(package)
      session = _get_session(team)
  
      session.put(
          "{url}/api/tag/{owner}/{pkg}/{tag}".format(
              url=get_registry_url(team),
              owner=owner,
              pkg=pkg,
              tag=tag
          ),
          data=json.dumps(dict(
              hash=_match_hash(package, pkghash)
          ))
      )